gtk:combo-box-popup-fixed-width (object)

object -- a gtk:combo-box widget
fixed -- a boolean whether to use a fixed popup width

The accessor for the popup-fixed-width slot of the gtk:combo-box class gets or sets whether the popup uses a fixed width matching the allocated width of the combo box. The gtk:combo-box implementation is deprecated since 4.10. Use the gtk:drop-down widget instead.